Answer: Elements found in group 1 (Alkaline Metals)
Explanation: Any element found in group 1, such as Lithium, Sodium, Caesium, or Francium, have similar properties as potassium. Atoms that are found in the same group on the periodic table have similar chemical properties.
briefly describe any example of an endothermic reaction and also mention the word equation
Explanation:
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Endothermic reactions are chemical reactions in which the reactants absorb heat energy from the surroundings to form products. These reactions lower the temperature of their surrounding area, thereby creating a cooling effect. Physical processes can be endothermic as well – Ice cubes absorb heat energy from their surroundings and melt to form liquid water (no chemical bonds are broken or formed).
When a chemical bond is broken, it is usually accompanied by a release of energy. Similarly, the formation of chemical bonds requires an input of energy. The energy supplied/released can be of various forms (such as heat, light, and electricity). Endothermic reactions generally involve the formation of chemical bonds through the absorption of heat from the surroundings. On the other hand, exothermic reactions involve the release of heat energy generated from bond-breakage.
Endothermic Reaction Examples
Ammonium nitrate (NH4NO3), an important component in instant cold packs, dissociates into the ammonium cation (NH4+) and the nitrate anion (NO3–) when dissolved in water
2)
Compare the atomic radius of an atom of bromine to the atomic radius of an atom
potassium when both atoms are in the ground state.
Copper chloride burns bright green 510x10^9 m what is the frequency in Hz?
Answer:
5.88 x 10⁻⁴Hz
Explanation:
Given parameters:
Wavelength = 510 x 10⁹m
Unknown:
Frequency = ?
Solution:
To solve this expression, we use the equation below:
V = f∧
V is the velocity = 3 x 10⁸m/s
f is the frequency
∧ is the wavelength
3 x 10⁸ = f x 510 x 10⁹
f = 5.88 x 10⁻⁴Hz
12 points and brainest
Answer:
wavelength
Explanation:
Answer:
wavelength
Explanation:
Which type of data confirms that one air mass is being replaced by another air mass in a particular area?
a-high wind speed
b-high air pressure
c-high air temperature
d- high levels of humidity
Que cantidad de agua (solvente) se necesitara para preparar 240 grs de una solucion al 25% en m/m ?
Answer:
180g
Explanation:
El soluto y el solvente son los componentes químicos que se mezclan en una solución. El soluto es una sustancia química, la cual puede poseer diferentes estados de agregación (es decir, sólido, líquido o gaseoso), que se se disuelve en un solvente; mientras que el solvente es una sustancia en estado líquído en la cual se diluye el soluto, formando una solución. La solubilidad de una sustancia química se define como la proporción en que una cantidad determinada soluto puede disolverse en una determinada cantidad de un solvente, a una temperatura específica. En este caso, 240 gramos (g) corresponde al 100% del contenido total de la solución, con lo cual la cantidad de solvente (agua) de una solución al 25% correspondería a la siguiente fórmula:
X = (75 x 240g) / 100
X = 180g
Dorothy left a frozen juice pop out on the counter. When she returned, the juice pop had melted into a liquid. Which of the following is true of the molecules in the juice pop?
Group of answer choices
The molecules had more kinetic energy when the juice pop was frozen.
The molecules were closer together when the juice pop was frozen.
The molecules became more tightly packed when the juice pop melted.
The molecules moved less freely when the juice pop melted.
Answer:
B) The molecules were closer together when the juice pop was frozen.
the discovery of protons and electrons most directly refuted or replace the idea that
- atoms contain a nucleus
- the Atom is indivisible
- the atom is electrically neutral
- the atom resembles plum pudding
Answer:
The atom resembles plum pudding
Explanation:
The discovery of the electron in 1897 by J. J Thomson and the proton in 1917 by Rutherford most directly refuted or replace the idea that the atom resembles plum pudding.
How can you determine if a molecule is held together by covalent bonds?
ann swims the length of a 50 meter swimming pool in 25 seconds. what is her average speed.
this is science
Answer:
2m/s
Explanation:
2meters/second
Help I’ll give Brainliest
A typical galaxy is a collection of about a hundred billion stars spanning a diameter of about -
A. 1 AU
B. 3DO AU
c. 1 light-year
D. 100,000 light-years
Answer:
D
Explanation:
ive watched this on a national geo show. But remind me again what is 1 Au and 3DO AU i forgot...
Which of these elements is the odd one out? Li Na Mg K Rb Cs
Answer: cc
Explanation:..
who else had to do a final model for the rust unit
Balance the chemical equation below using the smallest possible whole number stoichiometric coefficients.
P4(s)+NaOH(aq)+H2O(l)➪
PH3(g)+Na2HPO3(aq)
Answer:
P₄ + 4NaOH + 2H₂O → 2PH₃ + 2Na₂HPO₃
Explanation:
The given reaction expression is given as:
P₄ + NaOH + H₂O → PH₃ + Na₂HPO₃
To solve this problem, now we put coefficients a, b, c, d and e and we use a mathematical approach to solve this problem;
aP₄ + bNaOH + cH₂O → dPH₃ + eNa₂HPO₃
Conserving P: 4a = d + e
Na: b = 2e
O: b + c = 3e
H: b + 2c = 3d + e
let b = 1, e = [tex]\frac{1}{2}[/tex] , c = [tex]\frac{1}{2}[/tex], d = [tex]\frac{1}{2}[/tex], a = [tex]\frac{1}{4}[/tex]
Multiply through by 4;
b = 4, e = 2, c = 2, d = 2, a = 1
P₄ + 4NaOH + 2H₂O → 2PH₃ + 2Na₂HPO₃
Calculate the second volumes. 955 L at 58 C and 108 KPa to 76 C and 123 KPa
The second volume : V₂= 884.14 L
Further explanationGiven
955 L at 58 C and 108 KPa
76 C and 123 KPa
Required
The second volume
Solution
T₁ = 58 + 273 = 331 K
P₁ = 108 kPa
V₁ = 955 L
P₂ = 123 kPa
T₂ = 76 + 273 = 349
Use combine gas law :
P₁V₁/T₁ = P₂V₂/T₂
Input the value :
108 x 955/331 = 123 x V₂/349
V₂= 884.14 L
Four grams of magnesium react with an excess of dilute hydrochloric acid. Calculate the volume in liters of hydrogen gas collected over water at 300 K, if the vapor pressure of water at that temperature is 26.7 mm and the barometric pressure is 730 mm
What Is the Difference Between Molar Mass and Molecular Weight in HNO3?
Difference between molecular weight and molar mass
Hint : Molar mass of molecules is also called molecular weight . Its unit is gram per mole. We can calculate molar mass of molecule with the help of following rules; ... Molar mass of nitric acid (HNO3) =atomic mass of hydrogen + atomic mass of nitrogen +3× atomic mass of oxygen .
Answer:
answer
Explanation:
Sorry I do not know the answer, hope you have a great day
What are the parts of the atom & which one is gained or lost in order for an object to
obtain a charge?
Answer:
The parts of an atom are electrons, usually found in an electron shell around the nucleus of the atom, and protons and neutrons, found in the nucleus of the atom. Typically, electrons are gained or lost in order to obtain charge.
the two factors that combine to keep the planets in orbit are-
A.gravity and orbital speed
B.orbital speed and mass
C.mass and inertia
D.gravity and inertia
Answer:
D. Gravity and inertia
When it happens orbital motion occurs
HELP!!! ITS TIMED!!!
Acetylene on prolonged heating yields benzene.
Select one:
a. True
b. False
Answer:
I think true
if wrong correct me plsssssss
I will always help you understanding your assingments
enjoy your day
#Captainpower:)
Answer:
It is a commonly observed fact that the yield of benzene and other aromatic hydrocarbons is greatest when the heat is intense, or its application to the vaporized hydrocarbons prolonged, ...TRUE
The hydrolysis of ethyl acetate in alkaline conditions yields acetate ion and ethanol. The rate of the reaction increases 6.37 times its original value when the temperature is increased from 15°C to 45°C. Calculate the activation energy of this reaction.
Answer:
Explanation:
Hydrolysis is a chemical decomposition involving breaking of a bond and the addition of elements
of water. In this hydrolysis of ester (ethyl acetate) with an alkali (sodium hydroxide), HCl was
used as catalyst to accelerate it. 1ml and 2ml of ethyl acetate was injected separately into the
500ml reactor vessels which contains 0.05N of NaOH and thoroughly mixed. At regular time
interval, 0, 10, 20, 30, 40, and 90 minutes, 25ml of each of the samples were withdrawn into a
250ml conical flask containing 0.05N HCl, and titrated against 0.05N NaOH solution using
phenolphthalein as indicator. From the titre values, the hydrolysis involving the 1ml ethyl acetate
was faster than that of the 2ml ethyl acetate, indicating that the higher the concentration the faster
the rate of reaction. The rate constant after evaluation from the graphs was approximately
0.003min-1
cm-3
for the 1ml and 2ml ethyl acetate, signifying that while the r
write the fraction of the mass of kcl produced from 1 g of k2c03
Mass of KCl= 1.08 g
Further explanationGiven
1 g of K₂CO₃
Required
Mass of KCl
Solution
Reaction
K₂CO₃ +2HCl ⇒ 2KCl +H₂O + CO₂
mol of K₂CO₃(MW=138 g/mol) :
= 1 g : 138 g/mol
= 0.00725
From the equation, mol ratio K₂CO₃ : KCl = 1 : 2, so mol KCl :
= 2/1 x mol K₂CO₃
= 2/1 x 0.00725
= 0.0145
Mass of KCl(MW=74.5 g/mol) :
= mol x MW
= 0.0145 x 74.5
= 1.08 g
What do the elements Ni, and Tc have in common?
Answer:
I know that
Explanation:
nickel is like to and tc is like nickel they both have something
An example of a chemical change is
Mashing potatoes
Dew disappearing from the grass
Frying a hamburger
A magnet sticking to the refrigerator
Answer:
Frying a hamburger
Explanation:
when frying a hamburger you change the properties of the meat by applying heat and in the other answer choices the element is not changed.
What is the difference between nuclear fusion and nuclear fission?
Answer:
[Fusion: Nuclei Fuse together and release energy] [Fission: Pressure and energy is released. This release of energy, is what causes the unstable atom to split to an isotope. I hope this helps!]
[isotopes can split too. At least some.]
Explanation:
Imagine you are trying to push something heavy, fusion is how you can join together and help each other to push this heavy material.
Fun fact! Heavier materials have more inertia against other forces acting on them.
You push harder, harder and harder! Until its pushed.
This will release a lot of energy which escalates to an extended length.
It might not be the finest example, it helped me to understand the basics.
Fission. Imagine having so much energy, in this case, try thinking of so many people in a tight space. What do you do? You will eventually start to escape and leave the room. This is the act of splitting the atom.
This won't be the same than how it was before.
Again, Energy is released (energy!!).
For anyone struggling with this, although it might not be the best idea, I would recommend researching the more advaced options for this topic.
This will give you a wide range of information which can develop your current knowledge about, "Nuclear Fission and Fusion."
It will be difficult, it definitely was for me when I was a child (starting to study science).
Just keep trying, you'll get it.
Metals tend to have a_______
attraction for
electrons
Answer plz
Answer:
Metals tend to have a low attraction for electrons.
Young stars, just beginning their life in the galaxy, would contain mostly
A)
carbon
B)
helium
iron and nickel
D)
hydrogen and helium.
Answer:Hydrogen and Helium
Explanation: Young stars would contain first hydrogen, then helium.
Young stars, just beginning their life in the galaxy, would contain mostly hydrogen and helium. That is option D.
What are young stars?A young star is a newly formed luminous object that is found in the galaxy.
The young star is mostly made up of two very light elements called hydrogen and helium. They also shine by conversion of hydrogen into more helium.
Therefore, Young stars, just beginning their life in the galaxy, would contain mostly hydrogen and helium.
Learn more about galaxy here:
https://brainly.com/question/1995133
#SPJ2
He reaction produces 1.6 g of gas in 30 seconds.Calculate the mean rate of the reaction in the first 30 seconds.Use the equation:
Answer:
Mean rate of reaction produced = 0.533 g/sec (approx.)
Explanation:
Given:
Reaction produced = 1.6 gram
Time taken = 30 sec
Find:
Mean rate of reaction produced
Computation:
Mean rate of reaction produced = Reaction produced / Time taken
Mean rate of reaction produced = 1.6 / 30
Mean rate of reaction produced = 0.533 g/sec (approx.)
RNA is a single stranded nucleic acid that is read by ribosomes to
synthesize a cell's protein. True or false?
HELP I’ll give Brainliest
Answer: The first question’s answer is 2 and the second question answer is 3. 12.B, 13.C
Explanation:
